Wireless communication devices are now becoming commonplace in the electronics industry. Wireless networking of portable computers and associated devices is now replacing a large segment of the networking market. Wireless communication devices including wireless networking adapters, hubs and other equipment utilize radio transmitters and receivers to transmit data signals from one device or node to another. These radio transmitters and receivers must utilize a specific frequency band and protocol to accomplish this task. Since these wireless networks and communications areas may often overlap, standards, protocols and privacy protection are necessary. One current standard in the industry has been established by the Institute of Electrical and Electronics Engineers, Inc. (IEEE) and is known as IEEE 802.11. This standard comprises communications standards, protocol and equipment specifications for wireless communication equipment including privacy and encryption provisions.
Another emerging standard in wireless communications and networking, known as Bluetooth.RTM. is being established by a collaborative group of communications and computing companies. Devices incorporating Bluetooth.RTM. technology will utilize a micro-chip transceiver for communications between devices. Bluetooth.RTM. devices will transmit in the previously unused 2.4 GHz range. Bluetooth.RTM. technology promises to be a viable and economical networking solution for interconnection of cell phones, computers, printers, modems, computer peripherals, fax machines and other communications and computing devices. The size of the Bluetooth.RTM. transceiver will make it usable in devices as small as palm computers and cell phones.
Antennas are well known for enabling and improving transmission to radio receivers and from radio transmitters. Antennas can dramatically increase the range of radio transceivers, however most antenna designs function best when protruding from their host device. In small electronic devices protruding antennas are often vulnerable to breakage as the devices are often stowed in purses, pockets, backpacks and other areas where neglect can occur. A retractable or otherwise deployable antenna is more convenient and durable and occupies less space when retracted.
Known monopole antennas perform optimally when they can radiate against a ground plane. Performance is further enhanced when these antennas extend substantially perpendicularly from a central location on a ground plane. However, retractable monopole antennas that are centrally located on a ground plane often occupy a relatively large amount of space when the centrally located antenna and ground plane are retracted into a host device.